The present invention relates to a level measuring set for low-frequency signals with superimposed direct voltage.
The measuring time of automatic level measuring devices is basically determined by the lower threshold frequency of the measurement rectifier.
Coupling capacitors are generally used for coupling the level measuring set to low-frequency signals with superimposed direct voltage. These have a disturbing effect on the measurement time, since recharging processes occur in the coupling capacitors, caused by switching peaks, overloads, etc.
German Patent No. 38 316 678 discloses a circuit arrangement for measuring peak values of a time-variable signal superimposed on a direct voltage pulse, in which the direct voltage component is eliminated by inversion and addition of the inverted and non-inverted signal.